• Republicans are sharply divided by ideology on whether gay marriages ought to be legal, with three-quarters of conservative Republicans opposed to gay marriage in the AP-GfK poll, while those Republicans who identify as moderate or liberal are almost evenly split, 43 percent opposed and 42 percent in support.

• Support for gay marriage by region tends to mirror laws, with those in the Northeast and West where more states allow legal marriages for gay couples more apt to support it than those in the South or Midwest. Majorities support legal gay marriage in the Northeast and West (56 percent in each region), compared with 44 percent in the Midwest and 36 percent in the South.

• Younger Americans are more supportive than older ones, with about half of those under age 50 in favor of legal gay marriage in their state compared with just 33 percent of seniors. That trend holds across party lines, with Republicans under age 30 nearly three times as likely to support legal gay marriage as Republicans age 65 and older.

Among Democrats, 78 percent under age 50 support legal gay marriage compared with 55 percent age 65 or older.

The AP-GfK Poll was conducted May 16 to 19 using KnowledgePanel, GfK’s probability-based online panel designed to be representative of the U.S. population.

It involved online interviews with 1,354 adults, and has a margin of sampling error of plus or minus 3.0 percentage points for all respondents.

Respondents were first selected randomly using phone or mail survey methods, and were later interviewed online.

People selected for KnowledgePanel who didn’t otherwise have access to the Internet were provided with the ability to access the Internet at no cost to them.

DENVER — It wasn’t all that long ago that Republicans used gay marriage as a tool to drive Election Day turnout. But as public opinion on the issue has turned and courts strike down same-sex marriage bans, gay rights is evolving into a wedge issue for Democrats to wield.